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Green synthesis of poly­(isosorbide carbonate) (PIC) with remarkable properties is a huge challenge in industrial applications due to low molecular weight and harsh reaction conditions. We reported a novel pathway to synthesize high molecular weight PIC through melt polymerization of isosorbide (ISB) and dimethyl carbonate (DMC), which are derived from the biomass and CO2, respectively. The effects of metal ion-containing compound catalyst on chemical structures, terminal groups, and molecular weight of PIC in the process of melt polycondensation were studied. Compared with the best reported catalyst lithium acetylacetonate, the weight-average molecular weight (M w) of PIC was increased by using our preferred catalyst sodium tert-butoxide from 46 500 to 55 100 with the ISB conversion up to 99.0%, and the reaction time was decreased from 12 h to only 2.5 h, as far as we know, which is the highest M w value and the most efficient catalyst achieved by one-step method. According to the results of the experiment and simulation, we found that high catalytic performance was ascribed to the weak interaction energy of anion–cation of catalyst and the strong proton acceptance ability of the anion of the catalyst. Meanwhile, increasing the interaction energy of anion–cation of the catalyst could inhibit the occurrence of the methylation side reaction and interestingly the activated endohydroxyl groups of ISB were found to be more easily methylated. Finally, based on the captured and detected intermediates of the two-stages of the reaction, a possible mechanim for the synergetic effects of cation–anion through hydrogen bond formation was proposed.

Phenolic ionic liquid structure can be designed readily to control the molecular weight of isosorbide-derived polycarbonates.

A synthetic strategy for bio-based polycarbonate was developed via one-pot polymerization of renewable monomer isosorbide and dimethyl carbonate using eco-friendly organo-catalysts.

The structure-controllable imidazole-based dicationic ionic liquids were used to precisely adjust the molecular weight and thermal properties of isosorbide-based polycarbonate.

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The development of non-noble metal electrocatalysts with high-performance and low cost are promising to replace expensive Pt or Pt-based alloy electrocatalysts for the oxygen reduction reaction (ORR). Herein, we demonstrate the fabrication of N-rich metal-free electrocatalysts based on hard carbon nanotubes derived from carbonization of nanotube-like porphyrin-based conjugated microporous polymers (denoted as TPP-CMP) for ORR. Taking advantage of their high specific surface, excellent porosity, and importantly, exposed N–C active site originating from the N-doping carbon nanotubes with unique hollow cylindrical geometry, the as-synthesized TPP-CMP exhibits excellent catalytic activity for ORR in alkaline medium. It shows a half-wave potential of 0.83 V, an onset potential of 0.95 V (vs RHE), a high diffusion limiting current density of 4.6 mA cm–2, which is comparable to the commercial Pt/C catalyst. More importantly, the TPP-CMP manifests higher methanol immunity and long-term stability than that of commercial Pt/C (20 wt %) catalyst for ORR in an alkaline medium. Furthermore, TPP-CMP exhibits a favorable a 4-electron reduction of oxygen (n ≈ 3.95) and lower H2O2 yield. These results make the TPP-CMP promising candidate as efficient electrocatalysts for ORR. In view of the designable flexibility and synthetic diversity of porous organic polymers (POPs), the findings obtained from this study may also open new possibilities for the future tailored design of POPs for creation of high-performance, metal-free ORR electrocatalyst only by a simple calcination process.